The work done in increasing the length of a massless spring from its natural length 15 cm to 15.1 cm is 20 J. Work done in increasing the length from 15.1 cm to 15.2 cm will be:
1. | 20 J | 2. | 40 J |
3. | 60 J | 4. | 80 J |
A body of mass m moving at a certain speed suffers a perfectly inelastic collision with a body of mass M at rest. The ratio of the final kinetic energy of the system to the initial kinetic energy will be:
1. | \(m \over {m + M}\) | 2. | \(M \over {m + M}\) |
3. | \({m + M} \over m\) | 4. | \({m + M} \over M\) |
The potential energy of a particle of mass 1 kg free to move along the X-axis is given by \(U(x) = (3x^2-4x+6)~\text{J}\). The force acting on the particle at x = 0 will be:
1. 2 N
2. -4 N
3. 5 N
4. 4 N
Work done by frictional force during the walking of a man is:
1. positive
2. negative
3. zero
4. maybe positive or negative
A particle is moving such that the potential energy U varies with position in metre as U (x) = ( - 2x + 50) J. The particle will be in equilibrium at:
1. x = 25 cm
2. x = 2.5 cm
3. x = 25 m
4. x = 2.5 m
Select the incorrect statement about potential energy:
1. | A change in potential energy is equal to work done against the internal conservative force.
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2. | A change in potential energy is independent of the reference point.
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3. | A change in potential energy depends on the reference frame.
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4. | The potential energy at a point is not unique. |
A block of mass m is moving with speed v towards a spring block system. If the collision is perfectly inelastic, then the maximum compression in the spring will be:
1.
2.
3.
4.
The figure shows the potential energy function U of a system in which a particle is in one-dimensional motion. In which region is the magnitude of the force on the particle greatest? (x: position)
1. | OA | 2. | CD |
3. | AB | 4. | BC |
Which of the following is not a unit of energy?
1. watt-hour
2. joule
3. eV
4. N/m